DAGUPAN CITY, Philippines — Students in this city on Thursday returned a sea turtle and 10 tortoises to their natural habitat at the mouth of Pontok River here.

Westly Rosario, Bureau of Fisheries and Aquatic Resources (BFAR) Research Center chief, said the release of the water creatures served as a lesson on protection of animals to the seven college, 10 high school and 10 elementary students who joined the activity.

The students, led by Margarita Rosario, a third year molecular biology and biotechnology student at the University of the Philippines in Diliman, Quezon City, first released the tortoises toward Lingayen Gulf.

But being freshwater species, they seemed disoriented so the students collected them and took them to the river’s upstream.

The students were later toured at the fish cemetery where they listened to a lecture on sea creatures and offered flowers to marine animals buried there, as part of the center’s celebration of All Saints’ Day.

Rosario said the turtles have been surrendered to the BFAR center since 2011. The donors bought the turtles in the market or were sold to them in their houses but they immediately surrendered them to the center, he said.

The biggest was the 30-kg Olive Ridley turtle surrendered by Imelda Abalos and Raul Paiso of Binmaley town.

The 10 tortoises, which weighed between 450 grams and 1.1 kg, were taken to the center by residents of Calasiao, San Fabian, and this city.

The BFAR, Rosario said, has been keeping an 18-kg green sea turtle (Chelonia mydas) because its right fore limb is broken and is still weak.